The invention relates to coal or woodburning stoves and, more particularly, to such stoves having an inner fire chamber and a surrounding air heating space, the stove being insertable in a fireplace and usable for cooking and space heating.
Stoves which may be inserted in a preexisting fireplace are well known. The exterior design of such stoves is illustrated in Design patents Des. No. 244,136 issued to Buckner, Des. No. 250,204 issued to Turner, and Des. No. 199,656 issued to Rogers. Woodburning stoves which are usable for cooking and space heating are also well known. Such a stove is disclosed in U.S. Pat. No. 3,952,721 issued to Patterson.
High heat production efficiency has long been recognized as an important feature of space heaters. Coal and woodburning stoves have long been used for space heating but their efficiency has been far from optimum because a substantial portion of the heat produced has been lost through hot gases flowing out of the stove's flue pipe. A recently developed approach to increasing the space heating efficiency of coal and woodburning stoves has been to surround the heat conductive walls of the fire chamber with spaced outer walls and to circulate room air through the space between the fire chamber walls and the outer walls so that heat generated in the fire chamber is transferred through the fire chamber walls to the circulating room air as the air passes over the walls. However, prior stoves designed in accordance with this approach channel the circulating air over only a limited surface area of the fire chamber and therefore limit the amount of heat which may be transferred to the circulating air. U.S. Pat. No. 3,952,721 issued to Patterson discloses such a stove. In the Patterson stove, air flows into the air heating space through holes at the side of the bottom plate of the stove. The air then circulates upwardly along the side and back of the stove, upward to the top of the stove and across the top of the stove through the front vents. The air is thus heated from within the fire chamber along the side walls, a portion of the back wall and over the top wall of the fire chamber. Flue gases escape from the fire chamber through a vertical flue disposed at the back portion of the stove.
It is well known that air blowers, such as, electric fans, can also be utilized in coal and woodburning stoves to increase the volume of air circulated in the space surrounding the fire chamber to thereby increase the efficiency of heat transfer. Prior stoves utilizing such electric fans were generally arranged with the fans located in the rear or near the top of the stove. These arrangements have the disadvantage of subjecting the fans to the intense heat which normally develops at these locations which can result in overheating of the fan motor and electric wiring. The fan shown in U.S. Pat. No. 3,685,506 issued to Monsat, for example, is disposed near the top of the stove in an open space surrounding the inner fire chamber where the air is normally very hot and could cause overheating of the fan motor and electric wires.
Accordingly, an object of the present invention is to provide a space heating and cooking stove which has increased heating efficiency and reliability.